南阳122（Triangular Sums）

Triangular Sums

时间限制：3000 ms  |  内存限制：65535 KB

难度：2

 

描述

The n^th Triangular number, T(n) = 1 + … + n, is the sum of the first n integers. It is the number of points in a triangular array with n points on side. For example T(4):

X
X X
X X X
X X X X

Write a program to compute the weighted sum of triangular numbers:

W(n) = SUM[k = 1…n; k * T(k + 1)]

 

输入

The first line of input contains a single integer N, (1 ≤ N ≤ 1000) which is the number of datasets that follow.

Each dataset consists of a single line of input containing a single integer n, (1 ≤ n ≤300), which is the number of points on a side of the triangle.

输出

For each dataset, output on a single line the dataset number (1 through N), a blank, the value of n for the dataset, a blank, and the weighted sum ,W(n), of triangular numbers for n.

样例输入

4
3
4
5
10

 

样例输出

1 3 45
2 4 105
3 5 210
4 10 2145

 

来源

Greater New York 2006

//T(N)=1+2+3+.....+N ; SUM=1*T(2)+2*T(3)+3*T(4)+......N*T(N+1)

#include<stdio.h>
int main() 
{
    int m,i;
    scanf("%d",&m);
    for(i=1;i<=m;i++)
    {
        int num,sum=0,total=1;
        scanf("%d",&num);
        for(int j=2;j<=num+1;j++)
        {                
            total+=j; 
            sum+=total*(j-1);
        }    
        printf("%d %d %d\n",i,num,sum);        
    }
    return 0;
}

 //看懂题意后，水；